Liquid fuel burner



1942 A. R. w. RICHARDSON ,3,141

' LIQUID FUEL BURNER Filed July 25, 1939 2 Sheets-$heet 2 INVENTOR Y Andrew/Q WHc/zardson WW WM ATTORNEY.

Patented Dec. 22, 1942 Andrew R. W. Richardso assignor to The Babc Newark, N.

n, Beckenham, England, ock & Wilcox Company, J., a corporation of New Jersey Application July 25, 1939, Serial No. 286,357 I I r In Great Britain July 28,1938

6 Claims. (Cl. 299120) This invention relates to the construction and operation of liquid fuel burners, and'more particularly, to liquid fuel burners adapted for efficient operation over a Wide range of fuel output and in which the liquid fuel may be atomized either mechanically or by means of. a gaseous atomizing fluid.

One of the main objects'of my invention-is to provide a method of firing by liquid fuel in .which liquid fuel is delivered to the whirl chamber of a liquid fuel burner in such a manner as to cause a whirling and axial movement of the fuel therein towards a restricted discharge orifice, a gaseous atomizing fluid is delivered to the whirl chamber, in the neighborhood of the fuel discharge orifice in such a direction as to cause it to whirl therein in the same direction as and in contact with the liquid fuel, andthe pressure at which liquid fuel is'supplied to the burner is adjustable for the purpose of regulating the output of the fuel burner.

A further object is to provide in a liquid fuel burner having a whirl chamber with a. restricted discharge orifice at one end, ducts for, directing liquid fuel and a gaseous atomizing fluid respectively into the whirl chamber and so located and directed as to' cause both the liquid fuel and ph'ragm shown in Fig. 3;

Fig. 3 is'an enlarged sectional elevation of'the diaphragm member shown in Fig. 1;

Fig. 4 is a front or furnace end view of the dia- Fig. 5 is a diagram of the system of connections to the fuel burner; and

Fig. 6 is a graph illustrating the range of fuel s pp y burner output capacity available with apparatus constructed according to the invention.

the atomizing fluid to whirl in the chamber in I the sameangular direction.

A further and more specific object is to provide a simple and effective control mechanism for a liquid fuel burner of the character described by which the amount and pressure of the liquid fuel supplied is regulated in accordance with operating conditions and the supply of atomizing fluid regulated in accordance with the atomization needs of the fuel burner as determined by the pressure of the liquid fuel supplied.

The various features of novelty which characterize my invention are pointed out with particularity in 'the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of my invention.

Of the drawings:

Fig. l is a sectional elevation of a liquid fuel burner constructed in accordance with my invention;

Fig. 2 is a front or furnace end view on an enlarged scale of the slot or sprayer plate shown in Fig. 1;

direction before issuing from the restricted disi sprayer plate.

As illustrated in Figs. 1-4, the liquid fuel burner has an annular liquid fuel channel I surrounding a gaseous atomizing fluid channel 2, the

channels being formed by outer and inner concentric tubes 3 and 4 respectively. Each of the channels communicates with a cylindrical unobstructed whirl chamber at the furnace end of the fuel burner. The channel I communicates with the whirl chamber through inwardly inclined or obliquely converging ducts or passages 6 in a diaphragm member l5 which extend from the end of the channel I and open through the end wall of the whirl chamber 5 within a relatively small radius. The atomizing fluid channel 2'also communicates with the whirl chamber 5 through outwardly inclined or diverging passages l in the diaphragm member l5, having their discharge ends opening into an annular groove 33 in the front-or furnace face of the diaphragm member, which groove in turn registers with an annular groove 8 in the outer or'rear face of a slot or sprayer plate It defining the circular sides .of the whirl chamber. The

groove 8 communicates-through holes 9 with an annular groove'lfl in the front face of the A plurality ofducts or slots I I extend fromthe groove l0 along the front face of the plate 14 and open tangentially into the whirl chamber Sat symmetrically spaced points adjacent its forward end. On account of the skew disposition of the ducts 6 and the tangential disposition of the slots II with respect to the whirl chamber 5, both the gaseous atomizing fluid, such as steam, which may be supplied to the channel I and the. liquid'fuel which may be' supplied to the channel 2 will pass into the whirl chamber and rotate therein in the same angular charge orifice l2 at the end of a tapered extension of the whirfchamber in an orifice or nozzle plate l3 arranged at the front side of the sprayer plate, as a diverging atomized spray. The orifice plate l3, slot plate l4, and diaphragm l5, are held in assembled position on the front end of the tube 3 by a cap screw IS. The end of the,

pressure of inner tube 4 is held ina concentric position by a cylindrical extension of the diaphragm ii.-

The outer ends of the tubes 3 and 4 are screwed into a removable body member ll of the burner coupling which is removably held in contact with a fixed part I8 by'a pivoted yoke i8 and screw 18, whereby the corresponding liquid fuel and through the steam passages of the burner by seating on a valve seat 28 formed in the end of the valve body 19.. The valve stem is maintained of the valve H2 and without changing nozzles or making any other adjustment. The steam pressure at the burner was automatically maintained constantby the reducing valve I ii at 45 lbs. per sq. in. The non-return valve 21 in the steam conduit automatically closed when the oil pressure was about 85 lbs. per sq. in.,.so that over the higher part of therange the fuel was atomized by mechanical atomization only.

The amount of steam required to effect atomization even at the lowest burner output is small and asthe output increases the back pressure which builds up in the whirl chamber effects concentric with the valve seat by arms 28 connecting a central internally threaded sleeve 30,

into. which the valve stemis'screwed. with a sleeve member at slidable in the valve body",

and provided with a radial flange which limits the upward opening movement of the valve stem. The valvebody I! is screwed into the steam passages to the coupling part- II and is itself provided with coupling means for connection-with the steam supply. when the pressure difference on opposite sides of thevalve 21 is insufllcient to maintain it open against the tendency of ravity to close it, it will close and preelude any possibility of liquid fuel, from the whirl chamber backing up into the steam supply line.

In the burner supply system diagrammatically illustratedin Fig. 5, the liquid fuel is'withdrawn from a fuel tankiiili and, after flowing through the line")! past the stop valves I03 and In! and filter I05, is delivered by. a positivedisplacementpump lilfi'driven by a constant speed heated by an oil heater "it. The quantity of all delivered by the pump 108 is arranged to correspond to the quantity consumed by the burner at the maximum rating of the burner. From the line Ifll the oilpassesto the burner 109 through a shutoffvalvel l0 and in a regulable amount to the oil return line Hlthrough which it re- 1 electric motor to the supply line 101 after being 4 turns to the tank "I, control of the amount returned and consequently control of theburner .outputbeing effected by a control valve 1 I! in the return line.

Steam from any suitable source I is supplied through the line I. l 3 and after' passing through a stop valve ill, a reducing valve H5, and a shutoff valve lit'is delivered to the bumer IM. In one particular embodimentsteam is supplied to the burner at a constant pressure ofabout 20 to fuel'oil at the ,bumer between the limits of about 5 lbs. per sq. in. and 200 lbsper sq. in., perfect atomization being obtained throughout this range. Themost suitable steam pressure depends upon the natureIof theoil' and i pres 'a steam line drain H9, an oil tank vent I20 and a i branch steam line I2l for preliminary heating of .55 50 lbs. per sq. in. and a valve disposed between the pump and the burner is. adapted to vary the a progressive decreasein the steam consumption. The apparatus therefore is highly advantageous not only from the points of view of ease of control and excellence of atomization over a particularly wide range. but also from the point of view of economy in operation; Moreover, the low pressure and small quantity of the steam or other gaseous atomizing fluid used results in silent operationts. Y

Should'the back pressure in the whirl chamber beinsumcienttoresultin the closing of the nonreturn valve 21 at the lowest oil pressure at which the steam canbe dispensed with while still obtaining perfect atomization, the shut-off valve H8 may be closed by hand or a further valve may be provided which closes automatically in dependence on the-oil pressure when the said lowest pressure is attained.

Air may also be used as the gaseous atomizing fluid, the steam supply and reducing valve be- ,ing replaced bylmeans for supplying air at low pressure to the burner. The air supply may be one which also serves some other purpose, or it the best form of the invention now known to me.

those skilled in the art will understand that changes may bemade in-the form of the appa- "ratus disclosed without departing from the spirit of the invention covered by my claims, and

that certain featuresof my invention may some- '-times be used to advantage without a correspondiilg'use of other features. 1 p

-1. A method Ofoperating a liquid fuel burner havinga restricted discharge orifice at one end of a whirlchamber which comprises deliveringv liquid fuel under pressure to the whirl chamber tothe whirl chamber ataa point inthe neighborhood ofthe orifice and ina direction causing it to whirl inthe chamberin the same direction as the liquid fuel, maintaining the pressure I ofthegaseous atomlzing fluid' substantially constant-aditlsting the pressure at which the. liquid fuel is supplied to the burner to regulatethe-output [of the burnenand cutting off the supply of atomizingfluid .when the liquid fuel pressure the o'il withdrawn from the mm; beneath a hood The graph of Fig. .6 illustrates a wide range of burner output extending from 10 lbs.'of 'oilper hour to 650 lbs. per hour with perfect atomization throughout the range, obtained by varying the oil pressure at the burner between 5 lbs. per

sq; in. and 200 lbs. per sq. in. simply by operation exceeds the atomizing fluid pressure by a predetermined pressure differential. j

2. A liquid fuel burner having a cylindrical whirl chamber with a tapered extension terminating in a restricted discharge orifice, means for supplying liquid fuel to said whirl chamber including an annularsupply passage and a diaphragm member havingsymmetrically arranged converging passages opening through the side thereof forming the wall of said whirl chamber at the end remote from said orifice and in a direction causing a whirling of the liquid fuel while moving therein towards said orifice, and means cluding an atomizing fluid supply passage within said annular liquid fuel supply passage.

3. A liquid fuel' burner having a cylindrical whirl chamber with a tapered extension terminating in a restricted discharge orifice, means for supplying liquid fuel to said whirl chamber including an annular supply passage and a dia phragm member having symmetrically arranged chamber at a point adjacent converging passages opening through the side thereof into said whirl chamber at the end remote from said orifice and in a direction causing a whirling of the liquidfuel while moving therein towards said orifice, and means for supplying a gaseous atomizing fluid to said whirl chamber including a supply passage within said liquid fuel supply passage, diverging passages in said diaphragm member, and a slot plate having slots therein arranged tangentially to said whirl chamber at points adjacent said orifice and in a direction causing a whirling thereof in the same direction as and in contact with the liquid fuel.

4. A control system for liquid fuel burners comprising a liquid fuel burner having a whirl chamber terminating in a restricted discharge orifice, means for supplying liquid fuel under pressure to said whirl chamber in a direction causing a whirling of the liquid fuel while moving towards said orifice, means for supplying a gaseous atomizing fluid tangentially to said whirl chamber and in a direction causing a whirling thereof in the same direction as the liquid fuel, means for maintaining the pressure of the atomizing fluid substantially constant, means for regulating the pressure of the liquid fuel supplied, and

valve means responsive to said liquid fuel and atomizing fluid pressures for ply of atomizing fluid when sure exceeds the atomizing predetermined value.

5. A control system for liquid fuel burners comprising a liquid fuel burner having a whirl chamber terminating in a restricted discharge orifice, means for supplying liquidfuelunder pressure to said whirl chamberat the end thereof the liquid fuel presfluid pressure by a remote from saidorifice and in a direction causing a whirling of the liquidfuel while moving towards said orifice, means for supplying a gaseous atomizing fluid tangentially to said whirl said orifice and in a direction causing a whirling thereof in the same direction as the liquid fuel, means for maintaining the pressure of the atomizing fluid substantially constant, means for regulating the pressure of the liquid fuel supplied, and valve means in said atomizing fluid supplymeans and responsive to said liquid fuel and atomizing fluid pressures for automatically cutting off the supply of atomizing fluidwhen the liquid fuel pressure exceeds the atomizing fluid pressure by a predetermined amount.

6. A liquid fuel burner having a. cylindrical whirl chamber with a tapered extension terminating in a, restricted discharge orifice, means for supplying liquid fuel to said whirl chamber including an annular supply passage and a diaphragm member having wall of said whirl chamber remote from said orifice and in a direction causing a whirling of the izing fluid to said whirl chamber including a supply passage within said liquid fuel supply pas- ,sage and diverging passages from said atomizing fluid supply passage having their discharge ends connected tangentially to said whirl chamber at points adjacent said orifice and in a direction causing a whirling thereof in the same direction as and in contact with the liquid fuel.

ANDREW R. W. RICHARDSON.

cutting off the sup-- symmetrically arranged converging passages opening through the end 

